Current research in nutritional medicine indicates that the omega-3 fatty acids are essential components of the human diet. According to studies published in the British scientific journal Lancet, the observed low incidence of arteriosclerosis (fatty plaques development on the inner walls of the arteries which obstructs the blood flow), including coronary artery disease, chronic inflammatory disease and diabetes in Greenland Eskimos has been attributed to their traditional ethnic diet, consisting largely of meat from whale, seals, sea birds and fish. This diet is rich in fat and protein and low in carbohydrates, but it is extremely high in omega-3 polyunsaturated fatty acids, and especially rich in two omega-3 fatty acids: C22:6 (DHA) and C20:5 (EPA).
The most important omega-3 fatty acids are eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and α-linolenic acid (ALA).
EPA is a direct source of an important substance called prostaglandin E3, which is directly responsible for making blood platelets less sticky, thus leading to an easier flow of blood. EPA is, therefore, involved in processes that inhibit blood clots whose presence threaten to obstruct the circulation; this mode of action is particularly important in the small capillaries of the heart.
DHA (docosahexaenoic acid) is an omega-3 fatty acid of almost equal importance to EPA. DHA comprises a significant amount of the tissues that make up the human brain as well as a large part of the retina of the eye.
Some of the most dramatic effects of increased intake of omega-3 fatty acids are the lowering of high blood pressure, reduction of serum triglyceride levels, and an increase in clotting time, all positive steps in the prevention of heart and blood vessel diseases. These beneficial effects of omega-3 fatty acids have been noted in both clinical trials and epidemiological studies. Omega-3 fatty acids were found to be extremely useful natural substances powerful enough to normalize the high cholesterol and triglyceride levels that are so extensive in modern populations.
Omega-3 fatty acids have also been shown to slow down or prevent cancerous tumor growth, prevent blood vessels from closing following vascular surgery, improve inflammatory diseases such as rheumatoid arthritis and relieve symptoms of psoriasis. In addition, omega-3 fatty acids are essential for proper vision and brain development in newborns.
The average western diet is low in fresh fish and sea food containing EPA and DHA. On the other hand, it is high in refined carbohydrates and saturated fats. This kind of diet can lead to a serious deficiency in the raw materials necessary for proper platelet function in the blood stream.
Linolenic acid is essential for ensuring healthy skin condition. Moreover, oils containing large amounts of omega-3 fatty acids were shown to be effective in preventing skin wrinkles. The ingestion of these oils markedly lowers the cholesterol content in the blood. α-Linolenic acid is a fatty acid found in some plants and can be converted by the body to EPA and DHA. Plant sources of α-linolenic acid include walnuts and walnut oil, flaxseed, rapeseed (used to make canola oil), soybeans, spinach, mustard greens and purslane.
α-Linolenic acid is produced in high quantities in several plants, mainly hemp (up to 23% α-linolenic acid is pressed from hempseed) and flax (50%). These oils normally have an “off” flavor and are seldom used as edible oils due to their bad taste and smell. Conventional food oils, such as rapeseed (canola) and soybean contain only small amounts of linolenic acid (11% and 7% respectively).
Researchers believe that a 1:1 ratio of omega-6 to omega-3 (omega-6 is found primarily in vegetable oils like corn, safflower or sunflower) may be important in preventing heart disease. It seems that omega-3's and omega-6's continually compete for control of important biochemical reactions in the body. When the portion of omega-6 is higher than that of omega-3, it can lead to an overproduction of hormone-like substances called prostaglandins and leukotrienes. Large amounts of these hormone-like substances can disrupt the immune system, initiate the build-up of plaque formations on artery walls, form blood clots and trigger dangerously irregular heart rhythms.
Currently, the ratio in the American diet is about 10 omega-6 to 1 omega-3, a ratio, some experts say, which is a dangerous oversupply of omega-6 fatty acids.
Dietary fish oils containing omega-3 fatty acids are increasingly recommended for their antithrombic and hypolipidemic (lowering blood lipid) effects (Phillipson, Rothrock, Connor, Harris and Illingworthm, New England J. Med., 312:1210-16, 1985). Additional benefits of these oils are improvement of immunological function and fighting allergies (Leaf and Weber, New England J. Med, 318:549-557, 1988).
Omega-3 fatty acids from vegetable oils could provide all the above health benefits without any of the disadvantages of oil from animal source.
During ingestion of vegetable oil there is no uptake of cholesterol. Fish oils are a primary source of vitamins A and D. Most marine oils may supply potentially toxic amounts of vitamins A and D, by supplying a sufficient amount of EPA and DHA factors. Also, many vegetal omega-3 oils have a clean flavor have a good taste, at least as compared to bad tasting fish oils. Fish oils are usually contained in preservative-free gelatin capsules for convenience due to their bad taste and smell.
Aromatic (essential) oil derived from flowers of Salvia sclarea has been used up to date mainly as a perfume; this usage was known from the time of ancient Rome. Other secondary uses for this aromatic oil have been in the tobacco industry, and in herbal remedies to fight infection, and to regulate the digestive system. The natural habitat of the plant is in Syria, Italy and Southern France; and its growth requirements in terms of soil content are not particular. Currently, the former Soviet Union, North Africa, and Hungary are the largest producers of this oil, and prices range from $60-90 per liter of oil. The plant can withstand heat, and is found on mountainous terrain, where rainfall is not lower than 400 mm annually. The floral parts alone are used to produce the oil; inclusion of leaves will degrade the oil quality. Typically a single harvest of floral parts is performed. If harvest is performed prematurely, the oil will contain a large percentage of linoleic acetate, which lowers the quality of the oil.
No previous use has been made of the seeds of Salvia sclarea; previous uses, mainly as a perfume or essential oils, were from plant material derived from the flower.
WO 99/62356 concerns enhanced food for humans which has significantly higher omega-3 content by the use of oil obtained from Salvia hispanica seed. Salvia hispanica (Chia) is a summer annual belonging to the Labiate family. It originates in mountain regions extending from west central Mexico to northern Guatemala. Due to its endemic growth restriction to mountain regions of central and southern America and thus its natural habitat is very specific and growth requirements very particular, making seed grown from the plant not economical, the plants are not widespread and have not acquired wide commercial acceptance as a food source.
It should be emphasized that the presence of ALA omega-3 fatty acid in oil produced from the seeds of one or another plant does not in itself suffice to indicate that the plant will be a good and effective source for that fatty acid. The range of different parameters, such as commercial cultivability, climatic conditions, regulatory provisions, profile of the fatty acids, percentage of fatty acids, ratio of omega-3 to omega-6, stability, flavor, fragrance, color, acidity, moisture, toxins, allergens, presence of vitamins and antioxidants in the oil, as well as many other parameters, determine whether oil from a certain plant will be a good and effective source for ALA omega-3 fatty acid. Sometimes, one parameter alone, such as aftertaste (e.g. in flax oil or Matthiola oil), or overoxidation (in flax or Salvia hispanica oil), suffices to prevent use of the oil as an effective and stable source for ALA omega-3 fatty acid in a nutritional supplement. Obviously, such a plant source cannot be designated as a good and effective source, when a large number of drawbacks come together in terms of the parameters listed above.